From: Ezequiel Garcia <ezequiel@collabora.com>
To: linux-media@vger.kernel.org
Cc: kernel@collabora.com, Tomasz Figa <tfiga@chromium.org>,
linux-rockchip@lists.infradead.org,
Heiko Stuebner <heiko@sntech.de>, Jonas Karlman <jonas@kwiboo.se>,
Philipp Zabel <p.zabel@pengutronix.de>,
Boris Brezillon <boris.brezillon@collabora.com>,
Chris Healy <cphealy@gmail.com>,
linux-kernel@vger.kernel.org,
Ezequiel Garcia <ezequiel@collabora.com>
Subject: [PATCH v3 3/3] media: vidioc-enum-fmt.rst: clarify format preference
Date: Wed, 13 Nov 2019 14:56:03 -0300 [thread overview]
Message-ID: <20191113175603.24742-4-ezequiel@collabora.com> (raw)
In-Reply-To: <20191113175603.24742-1-ezequiel@collabora.com>
It has been decided to use the ENUM_FMT index value
as a hint for driver preference. This is defined purposedly
in a very liberal way, letting drivers define what "preference"
means.
For instance, the Hantro VPU driver indicates additional
processing to output a given format, and thus implicates
more CPU usage, which is enumerated after native (non-processed)
formats.
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
---
Documentation/media/uapi/v4l/vidioc-enum-fmt.rst | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst b/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst
index 399ef1062bac..8ca6ab701e4a 100644
--- a/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst
+++ b/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst
@@ -44,7 +44,9 @@ To enumerate image formats applications initialize the ``type`` and
the :ref:`VIDIOC_ENUM_FMT` ioctl with a pointer to this structure. Drivers
fill the rest of the structure or return an ``EINVAL`` error code. All
formats are enumerable by beginning at index zero and incrementing by
-one until ``EINVAL`` is returned.
+one until ``EINVAL`` is returned. If applicable, drivers shall return
+formats in preference order, where preferred formats are returned before
+(that is, with lower ``index`` value) less-preferred formats.
.. note::
--
2.22.0
next prev parent reply other threads:[~2019-11-13 17:57 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-13 17:56 [PATCH v3 0/3] Enable Hantro G1 post-processor Ezequiel Garcia
2019-11-13 17:56 ` [PATCH v3 1/3] media: hantro: Cleanup format negotiation helpers Ezequiel Garcia
2019-11-14 9:26 ` Philipp Zabel
2019-11-14 9:32 ` Boris Brezillon
2019-11-13 17:56 ` [PATCH v3 2/3] media: hantro: Support color conversion via post-processing Ezequiel Garcia
2019-11-14 9:46 ` Boris Brezillon
2019-11-14 9:48 ` Philipp Zabel
2019-11-15 15:44 ` Ezequiel Garcia
2019-11-15 16:10 ` Philipp Zabel
2019-12-05 14:33 ` Ezequiel Garcia
2019-12-05 14:46 ` Philipp Zabel
2019-12-05 16:02 ` Ezequiel Garcia
2019-11-13 17:56 ` Ezequiel Garcia [this message]
2019-11-14 9:32 ` [PATCH v3 3/3] media: vidioc-enum-fmt.rst: clarify format preference Boris Brezillon
2020-02-09 19:52 ` [PATCH v3 0/3] Enable Hantro G1 post-processor Nicolas Dufresne
2020-02-10 2:45 ` Tomasz Figa
2020-02-11 4:16 ` Nicolas Dufresne
2020-02-11 16:22 ` Nicolas Dufresne
2020-02-12 7:06 ` Tomasz Figa
2020-02-19 21:06 ` Nicolas Dufresne
2020-03-09 11:11 ` Tomasz Figa
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20191113175603.24742-4-ezequiel@collabora.com \
--to=ezequiel@collabora.com \
--cc=boris.brezillon@collabora.com \
--cc=cphealy@gmail.com \
--cc=heiko@sntech.de \
--cc=jonas@kwiboo.se \
--cc=kernel@collabora.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-media@vger.kernel.org \
--cc=linux-rockchip@lists.infradead.org \
--cc=p.zabel@pengutronix.de \
--cc=tfiga@chromium.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).